CountMinSketch C++实现

#pragma once
#include <vector>
class CountMinSketch
{
public:
	CountMinSketch(int w, int d) :width(w), depth(d), table(d, std::vector<int>(w, 0)){}
	~CountMinSketch();

    void update(int item) {
        for (int i = 0; i < depth; ++i)
        {
            table[i][hashFunc(item + i) % width]++;
        }
    }

    void update(std::string item) {
        for (int i = 0; i < depth; ++i)
        {
            table[i][hashFuncSring(item) % width]++;
        }
    }

    int estimateFrequency(int item) {
        int minFrequency = INT_MAX;
        for (int i = 0; i < depth; i++) {
            minFrequency = std::min(minFrequency, table[i][hashFunc(item + i) % width]);
        }
        return minFrequency;
    }

    int estimateFrequency(std::string item) {
        
        int minFrequency = INT_MAX;
        for (int i = 0; i < depth; i++) {
            minFrequency = std::min(minFrequency, table[i][hashFuncSring(item) % width]);
        }
        return minFrequency;
    }
private:
	int width, depth;
	std::vector<std::vector<int>> table;
	std::hash<int> hashFunc;
    std::hash<std::string> hashFuncSring;
};


CountMinSketch::~CountMinSketch()
{
}